Chlorine, heavy metals, pesticides – even residues of the drugs we take, they all end up in our drinking water. Here’s what you can do about it. By Lara Grinevitch BSc, ND

What is the problem with tap water? As Australian tap water makes its way through the catchment and distribution system, it meets many contaminants: livestock waste, fertilisers and pesticides from agriculture and industry, chemical run-off from industry, heavy metals from mining, and the waste from our own cities. Fortunately the tap water is ‘purified’ before it is finally sent to your tap, but what does this really mean?

In many respects Australian tap water is very good. All water regulators in Australia must adhere to guidelines laid down by the National Health and Medical Research Council (NHMRC). The latest set of guidelines is available to the consumer in the document Water Made Clear: A Consumer Guide to Australian Drinking Water Guidelines 2004. At first glance, the safety standards seem quite adequate. Municipal water is monitored for 70 different contaminants, including cryptosporidium, bacteria and some pesticides.

Chemical cocktail

But is this good enough? If you consider the thousands of chemicals that are polluting our environment, monitoring for 70 things is not very reassuring. The other problem is that Australian regulators monitor water according to health data for individual contaminants over the short term, rather than for the long-term effect of a chemical cocktail of over 300 chemicals found in food and water. And – make no mistake – the cocktail is much more toxic than the simple sum of the individual chemicals. When the body’s detoxification pathways become occupied with one toxin, they cannot take care of the others properly. Research has shown that when people are exposed to more than one pesticide, the blood concentrations of the individual pesticides are up to 100 times greater than during exposure to a single toxin.1

Another consideration is the fact that some toxins, such as lead from lead solder in your house pipes (legal in Australia until 1989), occur when the water is already on its way to your tap. Furthermore, chlorine, which is used to disinfect, and has been considered to be ‘safe’, has actually been linked to many problems, including increased rates of miscarriage. There is also the fact that some people, especially children and pregnant women, are more sensitive to toxins than the average population.

The bottom line is that even the best water regulators can monitor safety only according to health information that is widely available. For micro-organisms, the information is fairly good. This means that when you are told the water is ‘clean’, it is generally meant that the water is ‘disinfected’. Information on other toxins is sketchy, at best. Before you convince yourself that your tap water has been ‘tested’, you may want to ask exactly what it has been tested for.

Contaminants: A Moving Target

Every municipal water supply is going to differ in terms of the chemicals that it has to deal with. The following is a discussion of some of the most common issues in Australia.

Chlorine

Chlorination of water is regarded as one of the most important advances in modern civilisation. Effective water disinfection helped to remove deadly diseases, such as dysentery, typhoid and cholera. Chlorinated water has saved lives, but new evidence suggests that it may not be without cost in terms

Chlorine is extremely reactive when it is in its molecular form, so much that elemental chlorine simply does not exist in nature. The chloride ions in the table salt and our bodies are fundamentally different in terms of chemical behaviour and health. Humanity’s first real introduction to molecular chlorine was not until the early 20th century, when chlorine gas was liberated and bound to organic molecules. This marked the beginning of the chemical age, and was the direct reason for the invention of solvents, plastics, pesticides (e.g. DDT), dry-cleaning solution, and dioxin, which is considered to be one of the most toxic compounds known to humans. Today, there are about 15,000 chlorine-based chemicals in common use, and all of them are toxic, including the elemental chlorine used to disinfect water.

Chlorine has long been suspected of causing bladder and colon cancers, but new research shows that it may cause other problems. A Norwegian study in 2002 found that 5 glasses of chlorinated tap water per day increases the risk of miscarriage by 14%, and may increase the incidence of stillbirth and birth defects. 2 Chlorine can trigger thyroid disease by reducing the uptake of iodine.3 (Fluoride does the same). Chlorine also raises cholesterol levels4, possibly by damage to vitamin E. Consumption of elemental chlorine kills friendly intestinal bacteria, and decreases stomach acid, resulting in irritable bowel syndrome and gastritis. Showering in chlorine strips the moisture from hair and skin, and may trigger eczema.

Unfortunately, the direct effect of the elemental chlorine is just the tip of the iceberg. Because it is so reactive, chlorine binds with the organic matter in water supplies, forming toxic by-products such as trihalomethanes and chlorinated hydrocarbons. Chlorinated hydrocarbons are a class of molecules that also include dioxin and DDT, which are known endocrine disruptors, and they have been linked by 100s of studies to decreased sperm count, infertility and reproductive cancers, such as breast cancer.5

Non-chlorine methods of disinfecting water do exist, such as ozone and UV radiation. At the moment, none of these methods are considered to be cost-effective on a large scale (Ed note: ozone is used to treat many bottled spring waters, this treatment has its own issues), so chlorine may still be the best option for keeping water safe from bacteria until it reaches your tap. But why should this mean that you actually have to drink the chlorine? A carbon filter removes 99% of chlorine and chlorinated hydrocarbons. Chloramine, which is a combination of chlorine and ammonia, is now used in some Australian water supplies, as a supposedly safer disinfectant. Chloramine does not form chlorinated hydrocarbons, but the few by-products it does form, such as iodacetic acid, are potentially even more toxic. According to the American Environmental Protection Agency, iodacetic acid is the most toxic disinfection by-product ever tested.6

Bacteria: Blue-green algae and Cryptosporidium

Water contamination by bacteria is a serious problem worldwide, but fortunately, it is generally not an issue in treated municipal water. Australians who rely on rainwater used to take extra precautions in this regard. Also at some risk are those with lower immune systems, such as children, the elderly, and those on chemotherapy. According to research from the Harvard School of Public Health, 10% of hospitalised cases of childhood diarrhoea in the US are attributed to the drinking water.7

Chlorination is usually effective for preventing bacteria, but unfortunately, bacteria is not the only problem. Blue-green algae in Australian water supplies produce dangerous toxins that cannot be removed by disinfection. The toxins have also been linked with stomach upset, skin rashes, and a long-term risk for liver cancer. Blue-green algae can be removed by carbon filter. Another problem is the cysts of Cryptosporidium and Giardia, which are resistant to currently used disinfection processes. When ingested in large enough quantities, these parasites can cause digestive problems such as diarrhoea and intestinal pain.

Pesticides

Hundreds of different pesticides are used in Australia, and many of them are used within the catchment areas for our drinking water. Water regulators do consider pesticides, but only in cases of accidental spillage. According to the 2004 Australian Water Guidelines, “there may be agricultural activities within some catchments, but industrial and chemical industries are generally absent. Thus, regular monitoring for organic compounds may not be justified [except during accidental spillage]”. (page 10-8 Australian Water Guidelines)

But is this sensible? New research has linked chronic low level exposure to pesticides with serious neurological disease and cancer.8 Furthermore, pesticides do accumulate in the groundwater, even without “accidental spillage”. When American streams and groundwater were sampled in 1999, scientists found over 60 pesticides and their breakdown products, including chloroform, industrial solvents and pesticides9,10.

One pesticide is of particular concern. Banned in some European countries as a cancer causing agent, Atrazine is still legal in Australia and the US. In one 1999 US study, the pesticide was found in tap water delivered to 10.4 million people. In some of the samples, the chemical was found at 14 times higher than the EPA safety standard, and was believed to increase the lifetime risk of cancer by 20 times.11 11 Atrazine is also a proven endocrine disruptor, increasing the risk of hormonal imbalance, reproductive problems and cancers.4

Atrazine was also detected in Australian groundwater by a Department of Land and Water Conservation study in 1997. The level of Atrazine alone did not exceed safety guidelines for an adult, but the authors of the study were concerned about the levels of pesticide degradates, which were also present, but are not covered by safety guidelines. Australian guidelines also fail to account for additive effects of Atrazine with other pesticide compounds. Other pesticides were found, including diuron, fluometuron, metolachlor, simazine and trifluralin.12

Pesticides and their residues can be removed by carbon filters and reverse osmosis.

Volatile Organic Compounds (VOC)

These hazardous pollutants are common, and include petrol, benzene and some chlorinated hydrocarbons, such as perchloroethylene. Many VOCs are proven carcinogens. They are primarily of concern as air pollutants, but they do end up in water.

VOCs can be removed by carbon filters, but not by reverse osmosis.

Heavy Metals

Lead. Contaminates drinking water when lead building materials or paint leach into rainwater tanks, or when house pipes contain lead solder (legal in Australia until 1989). Monitoring for lead in the municipal distribution system will not detect contamination in the home. At the same time, a test of home water may miss the problem, because the majority of the lead is suspended in the first flow of water in the morning. Lead poisoning causes high blood pressure, headaches, joint pain, reproductive problems and many other symptoms in adults. In children, it has the devastating effect of impairing growth and brain development.

Mercury and cadmium. Enter the groundwater primarily from fossil fuel emissions, industrial smelting and mining operations. Mercury is considered to be a serious pollutant by the Australian National Pollutant Inventory, and is monitored in municipal water supplies.

Arsenic. A problem in parts of the world, such as Asia, where it is concentrated in the bedrock. It is not perceived to be a problem in Australia.

Heavy metals can be removed by reverse osmosis and metallic resin. Avoid first-flush lead by running the water for 30 seconds before using tap water in the morning.

Fluoride

Fluoride is unique as a water contaminant because it is added as medication to prevent dental cavities. It is the only example of mass medication in the world.

There is a strong lobby in Australia to fluoridate water, despite the fact that 98% of western European countries have discontinued it, including Germany, Belgium, France and most of England. Furthermore, the practise of fluoridation has been firmly denounced by many prominent scientists, including Dr J. William Hirzy, a senior member of the US Environmental Protection Agency, and Nobel prize-winner Dr Arvid Carlsson.13 These scientists argue that the decreased incidence in dental caries in the last decades cannot be attributed to fluoridated water alone, and that furthermore, fluoride’s benefits to teeth is from direct application, and not from ingestion.14

Fluoride is known to cause damage to bone and teeth called fluorosis, and it has been strongly associated with cancer, arthritis and nerve damage and metabolic disease.15 It is also believed to increase the absorption of aluminium. The use of fluoridated water for baby formula is of particular concern to nutrition experts.16

All major cities in Australia now have fluoridated water. Fluoride can be removed by metallic resin, reverse osmosis and ionisation.

Plastic

Plastic residues, such as phthalates may end up in the water from PVC pipes and plastic water bottles.17

Phthalates are endocrine-disrupting chemicals, and have been linked with hormonal imbalance and reproductive cancers.

Plastic water bottles are designed for single use only. Concentrations of residue increase with reuse, especially after the bottle is stored in the sun or a hot car.

Phthalates can be removed by carbon filters and reverse osmosis.

Pharmaceuticals

Medications and their breakdown by-products make their way into the water supply. A 2000 study by the US Geological Survey found residues from antibiotics, birth control pills, hormone replacement therapy, painkillers, chemotherapy agents, and antidepressants in 80% of streams sampled.18 The true extent of the problem is not known, but it is known that most pharmaceuticals pass into human waste unchanged, and that many drugs, such as oestrogens, may persist in the groundwater for years, Pharmaceuticals can be removed by UV light and carbon filters.

A drop in the bucket

The National Health and Medical Research Council (NH&MRC) advises that consumer filtration is necessary only for aesthetic reasons. This clearly does not take into account the long-term risk from exposure to the trace elements in treated water. We are lucky in Australia that our water is disinfected, but do not be fooled into believing that this is the same thing as purified. As consumers, we have the responsibility to our own health to take water purification one step further.

Unfortunately, the toxins in drinking water are only part of the story. We are exposed to toxins in many other ways. Chlorinated hydrocarbons, for example, are found in flyspray, dishwasher detergent and bathroom cleaners. Car exhaust and cigarette smoke are a primary source of exposure to heavy metals.

Luckily, our bodies are able to detoxify some of these molecules, so it is not necessary to avoid every molecule of toxin. We can, however, take measures to minimise exposure where possible. Removing harmful chemicals from the house, and filtering tap water are a good first step.